The various working radii of the boom and the
maximum and minimum radii at which the boom may be safely used with
and without outriggers shall be conspicuously posted near the controls
and shall be visible to the operator. A radius indicator shall be
provided. [29 CFR 1915.115(c)(1)]

Special precautions should be taken when placing a
crane on a vessel (barge) due to [ANSI B30.8-1982 Section
8-1.2.2(3).]:

Side loading of booms shall be limited to freely suspended loads.
Cranes shall not be used for dragging loads sideways. [29 CFR 1910.180(h)(3)(iv)]

Neither the load nor the boom shall be lowered below
the point where less than two full wraps of rope remain on their
respective drums. [29 CFR 1910.180(h)(3)(x)]

When two or more cranes are used to lift one load,
one designated person shall be responsible for the operation. This
person shall
be required to analyze the operation and instruct all personnel
involved in the proper positioning, rigging of the load, and the
movements to be made. [29 CFR 1910.180(h)(3)(xii)]

The operator shall not be permitted to leave his or her position at the controls while the load is suspended.
[29 CFR 1910.180(h)(4)(i)]